well, the page is on the wikipedia domain, it is a talk page regarding edits to the page (discussion among different Indians I presume.)

again as I understand it strictly speaking a foreigner should be casteless, and hence untouchable.

But that discussion implies that the actual behavior towards foreigners does not match that, which would seem reasonable to me. Indians will need to interact with foreigners, if they are without caste that would be a problem, so how to fit the foreign into the social system.